Bulldozer and excavator electric parts include components such as: 1. Battery: The battery provides the initial power to start the engine and operate the electrical system. 2. Alternator: The alternator charges the battery and powers the electrical system while the engine is running. 3. Starter motor: The starter motor turns the engine over to begin the combustion process. 4. Ignition system: The ignition system includes the spark plugs, ignition coil, and distributor, which work together to ignite the fuel in the engine. 5. Sensors: Sensors such as the oxygen sensor, temperature sensor, and pressure sensor provide information to the engine control module (ECM) to help regulate engine performance. 6. Wiring harness: The wiring harness connects all of the electrical components in the machine and provides power and signals between them. 7. Switches and relays: Switches and relays control the flow of electricity to different parts of the machine, such as lights, fans, and motors. Overall, electric parts play a critical role in the operation of bulldozers and excavators, and regular maintenance and replacement of these components is essential for safe and efficient operation.